In the manufacture of ring-shaped filamentary reinforced metal matrix composites, for example as illustrated in U.S. Pat. No. 4,782,992, a helical assembly of metal foil and filaments is disposed in an annular female chamber of a lower die and an annular male punch is pressed onto the assembly in a vacuum hot pressing device to consolidate the assembly and bond the metal foil and filaments into the desired ring-shaped densified composite. After consolidation, the ring-shaped composite is typically mechanically ejected at the high pressing temperature using one or more knock out pins.
Removal of the consolidated ring-shaped composite has presented problems, typically requiring a draft angle on the walls of the female chamber of the lower die. Removal can be especially difficult when consolidated ring-shaped composite has a small thickness after consolidation and lies deep in the female chamber. Vacuum hot pressing equipment without access to a knock-out pin has been used for pressing large ring-shaped composites; e.g., greater than eight inches in diameter, such that removal of the composite after consolidation is difficult.
It is an object of the present invention to provide tooling, such as a die set, for consolidating a filamentary reinforced metal matrix composite, which permits ready removal of the consolidated composite from the die set.
It is another object of the present invention to provide tooling, such as a die set, which permits use of a draftless female chamber in the lower die.
It is another object of the present invention to provide tooling, such as a die set, which permits ready removal of the consolidated composite without the need for ejector or knock-out pins.
It is another object of the present invention to provide tooling, such as a die set, which substantially prevents transverse or radial bulging of the preform during hot pressing.
It is still another object of the present invention to provide a consolidating method wherein the tooling, such as a die set, and a preform of the composite are cooperatively associated and enclosed within a gas impermeable envelope so as to allow hot isostatic pressing of the preform in the die set within the envelope.